Antitheft device for electric-lamp bulbs



Aug.7,1923. L464243 T. A. DICKINSON ANTITHEFT DEVICE FOR ELECTRIC LAMP BULBS Filed Avril 22, 1922 flNVENTOF-R:

Patented Aug. 7, W23.

tit

dlhlfai THOIKAS A. DICKINSON,

or YOUNGSTOWN, c1110.

ANTITHEFT DEVICE FOR ELECTRIC-LAMP BULBS.

Application filed April 22, 1922. Serial No. 556,045.

To all ur/wm if may concern Be it known that l, THOMAS A. DICKIN- son, a subject of the King of Great Britain, and a resident of Youngstown, in the county 6 of Mahoning and State of Ohio, have invented a new and useful Improvement in Antitheft Devices for ElectricLamp Bulbs,

of whch the following is a full, clear, and

exact description.

My invention relates to means for preventing theft of electric light bulbs, and will be better understood by reading the following description taken in connection with the accompanying drawing forming" a part thereof and in which- Figure 1 is a view showing a lamp bulb with my invention applied thereto and screwed into an ordinary socket, the socket being shown in section;

Figure 2 is a plan View of one element of the device;

- Figure 3 is a plan view of another element of the device;

Figure 4 is a central section of the element 26 of Figure 3;

Figure 5 is a plan View of another element, Figure 6 is a section on line VL-VI of Figure 5; and

Figure 7 is a view of a portion of a bulb as prepared for receiving the protective device. In Figure 1 of the drawings is shown an ordinary lamp socket 1 which may be of any desired construction. A lamp bulb 2 of the ordinary construction is adapted to be screwed into the socket 1. The socket shown comprises a metal portion 3 which is separated from the interiorly threaded socket 4 by insulation 5. One of the wires 6, connects with the socket 4-, and the other wire 7, connects with the central contact 8 of the socket. The contact 8 is insulated from the socket 4 by the insulating disk 9. The lamp shown is of the ordinary construction and is provided with a central contact 10 to which is connected one end of the filament 11. -The other end of the filament 11 is connected with the base 13, which is provided with threads in the ordinary manner and is adapted to be screwed into the socket 4. When the lziinp is screwed into the socket. the base is electrically connected with the socket l and the contactlO engages the contact 8 so -that a circuit is made from the supply lines f6 and 7 through the filament 11. The parts so far described are of standard construction and per form no part of my invention, and may be varied at will.

My device comprises the parts shown in Figures! to 6, inclusive, in combination with the elen'ients heretofore described. In applying my device to the ordinary lamp bulb, the edges of the central contact 11) are slightly raised by means ot'aknife or similar instrument. and the washer 14- placed around the portion 15 oi the base. The washer 14 takes the position shown in. Fignre 1. A washer 1G is then placed around the part 15 on the base and takes the position. shown in Figure 1.- The washer 1G is of insulating material, and "the openingtherein is made to fit the part 15 oi the base. The lock washer 17, shown in Figure 2, is then placed in the position shown in Figure 1, and acts to hold the washers 14 and 16 in place, the slot 18 being of suliicient size to receive the stem of the contact 10 of the lamp base.

The Washer 14 is preferably provided with two fiat portions 19 for a purpose which will appear later. The diameter of the washer 14 is somewhat larger than that of the base of the lamp and may be made of' any suit able material. The weight of the material from which the washer 14 is made depends somewhat upon the size of the lamp to which it is to be applied.

When the lamp is screwed into the socket. the edges of the washer 14 will engage the socket and will be bent slightly downward, as shown in Figure l. The shape of the base and the flexibility of the washer 14 will permit the base with the washer thereon to be easily screwed into the socket. and the wash ers 16 and 17 will act to hold the washer 14 in place so as to avoid short-circuits. If it is attempted, to unscrew the lamp "from the socket, the edges of the washer 14 will jam in the threads of the socket and will tend to hold the base in the socket. If suiiirient effort is applied to the lamp to unscrew the base, the washer 14- will be tightly jammed in the threads of the socket and the central contact 10 will be pulled out of the base and I the lamp rendered useless because the same cannot be again used until after another cen- 10 tral contact has been applied to the base and suitable connections made to the leadingin wires. By reason of the fact that the re moval of the base from the socket with this device applied renders the lamp useless, un-

ti rel parts may be easily washer across the two sides 19 is smaller I than that of the socket, as a result of which the arts will readily pass out of the socket.

y invention has many advantages, among which may be mentioned that it is simple, easily applied, is effective and may be re-used many times, is inexpensive, en

safe, and may be applied to a standard amp bulb without substantial alteration thereof.

I claim:

1. An anti-theft device for electric lamps, comprising a flexible member attached to the lamp base and overlying the end thereof, said member being adapted to jam in the threads of the socket upon attempted re- 'moval of the base from the socket, substantially as described.

2. An anti-theft device for electric lamps, comprising a flexible member attached to the base and adapted to assume a concave position as the b se is screwed into the socket and to jam in the socket upon attempted removal of the base from the through said central contact, substantially socket, substantially as described.

3. An anti-theft device for electric lamps, comprising a flexible member overlying the end of the lamp base and adapted to jam in the lamp socket upon attempted removal of the base therefrom, and insulating material overlying said flexible member and secured to said lamp base, substantially as described.

4. An anti-theft device for electric lamps, comprising a flexible disk attached to'the lamp base and having a1 diameter greater than that of the lamp socket, said disk being adapted to jam in the! socket upon at tempted removal of the ba se from the socket,

.- substantially as described 5. An anti-theft device for electric lamps, comprising a flexible member, and means for remoyably securing said member'to the center contact of a lamp base, said member" having a diameter greater than the lamp socket and being adapted to jam in the socket upon attempted removal of the base having diametrically opposite flattened sides from the socket, substantially as described;

6. An anti-theft device for electric lamps, consisting of a member attached to the cen-' tral contact of the lamp and having a portion adapted to engage the socket and to be bent in a direction towards'the filament whep ,thebase is screwed intothe socket, substantially, as described. i

7. An anti-theft device for ele'ctric'lamps,

consisting of a member attached to the central contact of the lamp and having a portion adapted to engage the socket and to be bent in a direction towards the filament when the base is screwed into the socket and to jam in the socket as the base is unscrewed from the socket, substantially as described.

8. The combination with alamp base having a central contact on' the end thereof, of means carried by said lamp base and adapted to interlock with means on the lamp socket upon attempted removal of the base therefrom, and 'means including insulating material interposed betwen said firstmentioned means and said central contact for securing said first-mentioned :means to said lamp base, substantially as'described.

9. The combination with a lamp base having a. central contact on the end thereof, of a flexible washer of greater diameter than said lamp base overlying the end of the latter, and a washer of insulating material interposed between said flexible washer and said central contact, substantially as de-- scribed.

10. The combination of a lamp base, a central contact thereon, a flexible washer on the end of said base and surrounding said central contact and of sufficient diameter to engage the socket when the base is placed in the socket, and a relatively rigid member engaging the other side of said flexible washer and of smaller diameter than the socket, said rigid member being attached to the base said central contact, substantially as described. v Y

12. The combination with a lamp base having a central contact on-the end thereof,

of a flexible washer overlying the said end and attached to said contact, said washer being of such dimensions as to pripherallyem gage the walls of the socket and thereby be flexed to permit the baseto be screwed into the socket and to jam in the socket upon attempted removal of the base thcrefro'mand to permit removal of the washer frpm the .socket upon rotation of said washer so that such flattened sides extend longitudinally of the socket, substantially as described.

' In testimony whereof I have hereunto set myhand.

gsnoMks A. DICKINSON; 

